The Greater Yellow-headed Vulture is very similar to the Lesser Yellow-headed Vulture Cathartes burrovianus and I am indebted to Bill Clark of Raptours for pointing out my original misidentification of photos 3 and 4 as this species.

Bill told me:
"...that the photos of the Lesser Yellow-headed Vultures are
actually Greater Yellow-headed Vultures. When perched, the wingtips of
lessers extend way beyond the tail tip, and in flight have very narrow,
long wings with high contrast between coverts and flight feathers.

Greaters are much larger and heavier. Their wings are quite wide and not as
two-toned as Turkey Vulture or Lessers. Their heads are more uniformly yellow, whereas that
of Lessers are tri-colored, yellow, red, and blue."

This also raises the question of habitat. I had always assumed that Greaters were only found in undisturbed forest. HBW says:"Seems to be confined to undisturbed lowland tropical forest in South America, and does not occur in more open habitats. Not found in disturbed forests."Ferguson-Lees says:"Extensive primary forest, mainly in tropical lowlands...; also seen over grassland close to forest"

The 3rd photo was taken in Roraima quite close to gallery forest in savannah but quite a few kilometers away from undisturbed forest. The 4th photo was taken near Vila Bela de Santíssima Trindade, Mato Grosso, close to small forest remnants but many kilometers away from undisturbed forest. My conclusion is that I must look closer at all Cathartes vultures and not jump to conclusions based on habitat.

Like other Cathartes species, it finds its food by its keen sense of smell while flying low over the forest. It feeds off the carcasses of forest animals such as monkeys and sloths.